I want you to go to your analytics, click on your organic search traffic from Google and see if there was an increase, decrease or no change after April 24th. Now, of course, keep note to track typical weekend referrals vs weekday. Here is this site's chart:

It seems like this site may have had a positive impact from Google Penguin but since we get news traffic, it is hard to tell.

Here is the poll, please take it and have all your friends take it as well. I'll share the results in a couple weeks: